Vacuum connection for molds



June 18, 1929. A, K W 1,717,607

VACUUM CONNECTION FOR MOLDS Filed June 13, 1927 fluyusc Kaa om Patented June 18, 1929.

UNITED STATES PATENT OFFICE.

AUGUST KADOW, OF TOLEDO, OHIO, ASSIGNOR TO THE VACUUM CASTING COMPANY OF TOLEDO, OHIO, A CORPORATION OF OHIO.

VACUUM CONNECTION FOR MOLDS.

\ Applicationfiled June 13,

This invention relates to a vacuum connection for a mold, and more particularly a connection for a mold section which is removably mounted upon a carrier. 7

The object of the invention is to provide a means by which an air tight connection between exhausting passages and the mold cavity can be made quickly and with the minimum opportunity for leakage.

Details of the invention will appear as the description proceeds.

In the accompanying drawings forming a part of this specification, Figure 1 is a side elevation of a portion of casting apparatus embodying the, invention; Fig. 2 is a section approximately on the line 2-2 of Fig. 1. In the embodiment of the invention disclosed-in the drawings, a mold carrier 10 supports a mold section 11 by means of a detachable connection ]2. A mating section 13 completes the mold, the mating section being supported in any desirable way.

. A vacuum chamber 14 in, the mold carrier is connected to an exhaust passage through a regulating valve 15. A control valve 16 governs the'connection of the vacuum cham-. ber 14 with the mold.

The casting cavity 17 in the mold is connected through anarrow slit with vacuum groove 18 in mold section 11. There are openings 19 through the wall of the mold into the vacuum groove, and stud pipes 20 are screwed into openings 19. Beneath control valve 16 there is a chamber 21 to which stud pipes 22 are'connected. Lengths of flexible hose 23 connect stud pipes 20 and'22. A con- 7 tainer 24 supports molten metal 25 in position to supply the moldwith molten metal when air is exhausted from the mold cavity.

In the construction shown, a block 26 is provided in groove 18 and held therein removably by screws 27 The block does not completely fill the groove, but leaves a space 28 back of the block and a slit 29 above the block. The mating mold section 13 is provided with a groove 30 in its face communicating with space 28 through slit 29. An extremely thin I passage 31 between the mold sections connects the mold cavity with groove 30.

It will be readily understood that-a certain degree of vacuum is maintained continuously within chamber 14. When the mold is to be filled its inlet is immersed in the molten metal and valve 16 is opened, whereu on the air moves from the mold cavity t rough great, there results spurting of the metal into largely, it has been customary to connect the 1927. Serial No. 198,491.

vacuum groove 18, openings 19, stud pipes 20, hose connections'23, stud pipes 22, chamber 21, and valve 16 to vacuum chamber 14.

In filling molds with metal, especially with metalwhich is fiuid in the molten condition, the force with which the metal is moved into the mold must be carefully regulated. If thedifi'erence between the pressure on the metal and the pressure in the mold cavity is too the cavity with resultant openings in the casting. If the differential pressure is too little, the metal solidifies in the cavity before the cavity is completely filled, and therebyimlperfect castings are produced. For this reason the degree of vacuum in the mold cavity must be accurately regulated.

It is desirable to have the mold sections readily removable from the carrier, as it is necessary to change the molds frequently for various reasons. In the construction of molds filled by the vacuum method, in glass making and similar operations where the vacuum method of filling the mold has been used mold cavity to the exhausting passages through the connections of the mold sections to the mold carrier. Where this is done, it is diflicult to make air tight connections, and furthermore the leakage whch is almost inevitable in the joints varies constantly from slight changes in the position of the mold section and because of varying temperatures. The result is that the degree of vacuum in the mold is aifectedby the leakage, and. the effect of this leakage is constantly varying, so that it is impossible to regulate the vacuum within themold as accurately as is desirable when casting fluid metals. By the connections disclosed in this application the likelihood of leakage is practically eliminated, and any leakage which does occur is substantially constant, so that the degree of vacuum within the mold can be accurately regulated.

The use of block 26 results in the distribu- 100 tion of the air along slit 20 when it is exhausted from groove 30, so that there is no material tendency for the metal to be drawn directly towards vacuum openings 19 more than toward other portions of the vacuum 105 entrance of the metal to the exhaust passages. 119

Any small amount that may be drawn in through slit 29 solidifies in space 28, and removal of'block 26 enables groove 18 to be quickly and easily cleaned. Comparatively serious difiiculty would arise if the metal could be drawn directly into passages 20.

It will be readily understood that various changes can be made in the exactconstruction of the apparatus within the terms of the ap-' pended claims.

hat- I claim is:

1'. A mold having therein a casting cavity and a vacuum chamber connected with said cavity through anarrow slit, a carrier for the mold,"a detachable connection for the mold to the carrier, there being a vacuum chamber within the carrier and detachable vacuum connections between the vacuum chamber in the carrier and the vacuum chamber in the mold independent of the detachable mounting of the mold upon the carrier.

2. A mold having therein a casting cavity and a vacuum chamber connected with said cavity through a narrow slit, a carrler for the mold, a detachable connection for the moldto the carrier, there being a vacuum chamber within the carrier anddetachable pipe connections between the vacuum chamber in the carrier and the vacuum chamber in the mold independent of the detachable mounting of the mold upon the carrier, said connections comprising a studpipe leading from the vacuum chamber in the carrier, a'

stud pipe leading from the vacuum chamber trance to the pipe of any metal passing through said passage into said chamber.

In testimony whereof, I have hereunto signed my name to this specification.

1 AUGUST KADOVV. 

